1. G. Agricola: ‘De Re Metallica’ (1556), (trans. L. Hoover and H. Hoover), 421; 1950, New York, Dover Publications.
2. M. Drabble: ‘A natural curiosity’, 308; 1989, New York, Viking Press.
3. R. J. Fruehan and C. L. Nassarella: Alex McLean Symp. Proc. 205–216; 1998, Warrendale, PA, ISS.
4. Blast Furnace Phenomena and Modelling